Tag: biotin

Many clinical laboratorians received questions in the past few months from clinicians about biotin interference on laboratory tests. Although biotin interference is not something new to most clinical chemists, it became more of a concern for clinicians since FDA released a safety communication warning to the public and healthcare professionals that “Biotin May Interfere with Lab Tests” in Nov 2017.

Why does biotin interfere with some laboratory tests?

Immunoassays employed in clinical laboratories often use biotin-streptavidin linkage to separate bound antibody-antigen complex from unbound components. For example, in a sandwich immunoassay setting, analytes bind to signal antibodies and biotinylated capture antibodies, which are immobilized on streptavidin-coated solid phase via biotin-streptavidin binding. In the excess of exogenous biotin, it interferes the binding of biotinylated antibodies and streptavidin, causing erroneous results.

Owing to assay design, tests that utilize the biotin–streptavidin linkage have different tolerance on biotin interference. There has been recent publications that summarized the tolerance level of biotin on commonly used immunoassays from different manufacturer platforms (1, 2). The recommended daily intake (RDI, 30 µg/day) of biotin do not typically interferes with laboratory testing. However, many over-the-counter dietary supplements may contain biotin much higher than the RDI, and the level used for treatment of multiple sclerosis or some other diseases can be even higher. These levels of biotin can cause either falsely high or falsely low test results.

As high-dose biotin use has been increased among general population for nutraceutical purposes, it requires clinicians’ awareness of biotin interference and communication with laboratories to identify incorrect laboratory results. It may require patients to discontinue dietary supplements containing high dose biotin for a period of time before blood drawn to minimize potential biotin interference with testing.

-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.